Expansion reamer for earth drills



March 5, 1957l F. K. vEAsMAN 2,783,974

EXPANSION REAMER FOR EARTH DRILLS Filed Nov. 12, 1953 2 Sheets-Sheet l 50' .u j? g 44 Ilm wir March 5, 1957 F. K. vEAsMAN EXPANSION REAMER FOR EARTH DRILLS v 2 sheets-sheet 2 Filed Nov. l2, 1953 0 A, @V4 4 www l 4 w M ad w w Ow @w JM 9.5 Q? Q M, e 3 M f? 2 WW Y z fw 'lll1 7 2,783,974 Ice A Patented Mall# 5,1957

EXPANSHN REAMER FOR EARTH DRILLS Frank K. Veasman, Oak Forest, Ill., assigner, by mesne assignments, to Allis-Chalmers Manufacturing Company, a corporation of Delaware Application November 12, 1953, Serial No. 391,619

2 Claims. (Cl. Z55-74) My invention relates to expansion reamers for earth drills, and is particularly directed to reamers'which are n used with an earth auger to enlarge a hole drilled by the auger, in ordinary earth or earth which offers a high resistance to drilling.

While the ordinary truck mounted or portable drilling rig is sufficiently powerful to` drill holes of diameters up to forty-two inches in ordinary earth, the rigs are as a rule unable to drill holes much larger than twenty-tour inches, when the earth is frozen, rocky, or in some other condition or of some other characteristic which oiers great resistance to drilling. Since the drills must be operated in both ordinary earth and other earth offering great resistance to drilling, it is inadvisable to construct the drilling rigs of greater power capacity and thereby greatly increase their cost because the drilling apparatus would be operating far below its power capabilities most ot' the time. Such drilling apparatus would not be mechanically or economically etlicient.

in the past, the drill operators in the tield have attempted to drill large diameter holes, for example a sixty-inch diameter hole, in earth of adverse drilling characteristics by first drilling a hole with a small auger, for example, a twenty-four-inch diameter auger. The twentyfour-inch auger is then removed from the hole and replaced on the spindle by a forty-two-inch diameter auger. The operator then attempts to drill a second hole concentric with the rst. Assuming such a second hole is made, the operator then removes the forty-two-inch auger and replaces it with a ifty-two-inch augerand attempts to drill still another hole concentric with the second. The tifty-two-inch auger is replaced with a sixty-inch auger and the final hole is drilled.

Experience has shown that succesfully drilling concentric holes of increasingly larger diameters is extremely dicult since the enlarging augers will not feed properly I have overcome the afore-mentioned difficulties as well as many others by providing an expansion reamer which is attached to the drill spindle above an earth auger. With my device, large diameter holes may be drille-d through frozen, rocky or other drill-resistant earth by a normally powered drilling rig with a minimum of difficulty. For example, by utilizing two expansion reamers and twelve and twenty-tour-inch angers, holes ot" all the above-mentioned diameters could be bored as well as holes of any diameter between twelve and sixtytwo inches. Obviously, this greatly reduces the number of augers that must be provided to fully equip a drilling rig.

Accordingly, an object of my invention is to provide an expansion reamer which is attached to a drill spindle j, above an earth auger.

Another object of my invention is to provide an expansion reamer, which is attached to a drill spindle, in which the digging surfaces are substantially '180 apart to balance any forces tending to cant the spindle and thereby prevent the spindle and reamer from wobbling.

Another object is to provide an expansion reamer for earth auegrs which give satisfactory service When used in ground that is difficult to drill, is quickly and simply attachable to a drill spindle and is easily and quickly' adjusted to various cutting diameters. v

Another object is to providean expansion reamer which is secured above an earth auger tothe drill spindle and which causes the earth loosened thereby to fall upon the earth auger for ready removal from the hole.

Another object is to provide a connected expansion reamer and earth auger, which auger is disposed within a pilot hole and serves to maintain the spindle centrally of the pilot hole to guide the reamer.

Still another object is to provide an expansion reamer which may be used to cut through frozen or rocky earth or earth which otherwise oiers a high resistance to drilling.

A further object is to provide an expansion reamer which is used in conjunction with an earth auger to ream out a large diameter hole from a pilot hole.

These and other objects and advantages will become apparent as the description proceeds and is read in conjunction with the drawings, in which;

Fig. l is a side elevational view of my expansion reamer, which is adapted to cut through ordinary earth,

i and a flat type earth auger secured to a drill spindle and and cant the spindle to cause wobbling of the augers. v

Successively enlarging the holes with separate augers is consequently a time consuming task. Furthermore, drilling consecutively larger holes requires that a plurality of earth augers be available to the operator.

My invention is by no means restricted to use in highly drill resisting earth and is used as wellin ordinary earth, and in either event greatly reduces the number of angers that must be carried with each drilling rig. Since the drilling rig would be overloaded when holes larger than forty-two-inch are drilled in ordinary earth,-when it is desired to drill a sixty-inch hole, the operator may, for example, drill successive concentric holes of thirty-sixinch, titty-two-inch, and sixty-inch diameters.

lt has been the practice, as pointed out hereinbefore, to provide several augers of different diameters for each drilling rig to enable different sized holes to be drilled.

As an example, a well-equiped drilling rig may carry nine augers having diameters of l2, 18, 20, 24, 30, 36, 42, 52 and 62 inches, repectively. Providing this many augers represents a material expense and a problem of transporting all of them with the rig.

positioned within a pilot hole;

Fig. 2 is a plan view of Fig. l;

Fig. 3 is a sectional view taken on line 3 3 of Fig. 2; and

Fig. 4 is an isometric view of another form of my expansion reamer, which is adapted to cut through earth which has a high drilling resistance, and a double-flight helix earth auger. o

Eigs. l, 2 and 3 show an expansion reamer which is adapted for use in earth of ordinary drilling resistance while Fig. 4 shows a modified reamer which is adapted for use in earth of high drilling resistnce such as frozen or rocky ground. The only difference in the two expension reamers lies in the shape of the cutting tool and in the manner in which the cutting tool is secured to the expansion reamer, as will be hereinafter more fully explained.

In Figs. l and 2, a standard fiat-type earth auger 10 and expansion reamer, generally designated 12, are carried on a drill spindle 14 with the earth auger disposed below the expansion reamer.

A collar 16 is secured to the spindle 14 and serves t0 Ihold the reamer against axial movement along the spindle. A spacing sleeve 13 and the expension reamer 12 are slidablymounted on spindle 14 below the collar 16; The

earth auger is secured to the end of spindle 14 by means of ehucl; 20. Thus, the sleeve 13 and reamer 12 are held against axial movement along the spindle 14 by collar 15 and chuck 25J, but may be readily removed by sliding them off the spindle when auger l@ and chuck have been withdrawn from the end of the spindle.

Reamer 12 comprises a central housing 22, a pair of projectable and retractable cutter supporting arms 2d, blades 26 and adjusting bolts 28. Housing portieri 22 has two elongated square holes or apertu 3d (Fig. 3) into which arms 24 'are slidable. The dimensions of apertures are such that arms snugly tit therein. The arms 24 have formed therein threaded bores 32 (Fig. 3). Bolts 2S have a threaded portion 3:. apted to lit within threaded bore 52, a larger nnthreaded portion 36 disposed loosely within an nnthrcaded bore 3S in housing 22, and a reduced head portion 4d which extends through a bore 42 in one face of housing 22. A washer 44 is secured to bolt 23 by a pin The bolts 28 are secured within the housing 22 against `axial movement since the unt readed portion 36 and washer abut opposing portions of housing 22 at each end of the bore 42.

Arm 24 and bolt 2S are connected to the housing 22 by first threading the bolt 2S into threaded bore 32 and then sliding the bolt 23 and arm 255 into square apertures 30 of the housing until the reduced head portion of the bolt extends through bore d2. The washer 44 is slipped over head portion il of bolt 28 and pin 46 is secured in place. rotation in apertures 3i), and since bolts 23 are held against longitudinal movement relative to housing 22, turning bolts 28 will thread the bolts into or out of arms 24 and cause the arms to be moved further into or out of apertures 36, respectively. Movement of arms 24 controls the cutting diameter of the reamer.

The housing 22 carries a collar 48 (Figs. l and 3) which extends through the housing 22 and is secured thereto. The collar 48 has a square central opening which has dimensions such that the square spindle i4 snugly slides therethrough and provides a positive means for transmitting rotation of the spindle to the reamer. The resistance to rotation oiered by the earth to the blades 26 will be transmitted to the spindle 14 through the arms 24 and 'housing 22, and, therefore, reinforcing brackets 59 are secured as by welding to the housing 2?. at the points of greatest stress.

Cutter blades 26 are carried on the outer ends of arms 24. The blades 26 are rigidly secured, as by welding, to members 52 which, in turn, are rigidly secured as by dovetailing, to a routed-out portion on the ends of arms 24. The blades 26 having a leading face 54, are disposed obliquely to a vertical plane taken through the longitudinal axis of arms 24 and to ia vertical plane perpendicular to the longitudinal axis of arms 24. The oblique disposition of the blades 26 causes earth which is pushed ahead of the blades to move inwardly and onto the earth auger. By arranging the blades 26 in substantially diametrically opposed relation to each other at equal radial distances from the vertical axis of the auger 1G, forces applied to the blades from the earth upon application of driving torque to the spindle i4 will `have no tendency' to move the spindle 14 out of its vertical position.

As previously stated, the expansion reamer shown in Figs. l to 3 is for use in ordinary soil and, in operation, is used to ream out a larger hole from a pilot hole. With the arms 24 in a retracted position, i. e., the blades 26 disposed within the circumference of the earth auger 10, a pilot hole is dug by means of auger itlsuch as that indicated at in Figs. l and After the pilot hole is dug, the reamer 12 and auger l@ are raised from the pilot fhole and the bolts 28 are rotated to move the arms 24 outwardly relative to the housing 22,. Scales 53 Since the arms 24 are held against may be provided on the upper face of arms 24, if desired, to indicate the extent of movement of the arms 24. After the arms 24 are extended the desired amount, the earth auger 1d is lowered into the pilot hole and the pilot hole is enlarged by rotating and feeding the spindle to force the blades 26 into the earth. As the blades 26 dig into the earth, the earth loosened by these blades will be forced inwardly and onto the earth auger 1i). When the earth auger 1t) becomes fully covered with dirt, the spindle is raised and the dirt is spun off of the auger.

if the earth through which the hole is to be drilled is not exceptionally drill resisting in nature, a pilot hole of the diameter of anger 1t) may be enlarged to final size by adjusting the arms 4 to the full diameter of the desired hole and drilling with the reamer until the final depth of the hole is reached. More frequently, however, several passes with successively changed settings of the reamer will be required to enlarge the hole to its iinal diameter. it will be appreciated that the volume of dirt that must be removed to provide a hole varies with the square of the diameter. Hence, to drill a sixty-inch hole requires four times the work expended in drilling a thirty-inch hole. Assuming that the auger 1t) is thirty inches in diameter and that the cutter blades 26 cut an annular groove nine inches in radial width, expanding a thirty-inch hole to a sixt` -inch hole will ordinarily require at least two settings for the expansion reamer, the rst setting at a forty-ve-inoh diameter' and the second setting at a sixty-inch diameter.

Ordinarily the surface of the earth is rather dense and compacted and has a surface layer which is called hard pan which may Vary in depth from one to fifteen or more feet. Assuming that the hard pan is tive feet thick and a hole of a sixty-inch diameter is to be drilled to a depth of ten feet, the operator may, as a rst pass, drill a pilot hole having a diameter of thirty inches to a depth of ten feet with the thirty-inch diameter auger 1t?. During this first pass the reamer is retracted within the diameter of the auger 10. After the pilot hole is drilled, the reamer would be set to a drilling diameter or" approximately forty-five inches and, as a second pass, a hole having a forty-ve-inch diameter would be drilled to a depth of approximately fifteen inches. The reamer would then be withdrawn from the hole and prepared for a third pass by adjusting it to a larger cutting diameter. Assuming that the third pass is to be made at the nal cutting diameter of sixty inches, the reamer is adjusted to that diameter and used to drill to a depth of fifteen inches. The reamer is then removed from the hole and readjusted for a cutting diameter of forty-rive inches and a fourth pass is made with the reamer to ream out the fhole to a depth of thirty inches. The reamer is adjusted again to a sixty-inch cutting diameter and a fifth pass is made to drill a sixty-inch diameter hole to the depth of thirty inches. This procedure is continued until the hard pan `has been penetrated and the soft earth therebelow reached. The remaining tive feet of the hole may be :drilled through the softer earth underlying the hard pan by simply setting the reamer to a sixty-inch cutting diameter. The reamer will cut a nine-inch radi'. width groove leaving a six-inch ridge which will be forced Onto the auger lf3 as the drill is powered down. ln soft earth this ridge of six-inch width has a tendency to crumble and offers no great resistance to downward movement of the reamer.

By teaming the hole in steps, as described above, the earth auger 1G will oe 1disposed within the pilot hole 56 iat all times that the reamer is operatively digging and thereby enable the auger to act as a guide for the reamer l2 and spindle 14. Gbviously, the depth of a step-cut must be less than the vertical distance between the bottom of the blades 26 and the lower circumferential edge of the auger lil in order that the auger will be disposed within the pilot hole 56 at all times when the reamer 12 is operative.

Various other modes of operation, of course, are possible and it should be appreciated that at various stages of the drilling operation the reamer and earth auger will be withdrawn from the hole in order that dirt loosened by the reamer may be removed from the hole.

Fig. 4 shows a modication of my expansion reamer which is used to drill through earth which has high drilling resistance. The reamer 12A is shown connected to the spindle 14 above a double-flight helix earth auger A. The only diierence between the expansion reamer `of Fig. 4 and that of Figs. 1 through 3 resides in the type of cutter that is secured to the ends of arms 24. Similar numerals have been used in Fig. 4 to indicate like parts shown in Figs. 1 to 3.

Cutter bits 60 shown in Fig. 4 are formed of heavy bar stock and secured Within the arms 24 by means of lock screws 62. The cutter bits 60 are secured to the arms 24 so that they have a cutting angle and a rake angle. The cutting angle which may, for example, be thirty degrees is the angle between the longitudinal axis of the cutter bit and a vertical section taken transversely through the arm 24, while the raking angle, which may, for example, be fteen degrees, is the angle between the longitudinal axis of the cutter bits 60 and a vertical plane taken longitudinally through the axis of the arms 24. The cutter bits 60 are capable of standing the shocks produced when the expansion reamer is used in frozen or rocky ground.

The operation of the expansion reamer shown in Fig. 4 is generally the same as that described for the expansion reamer of Figs. 1 to 3 except that the pilot hole will be enlarged in smaller increments when the expansion reamer of Fig. 4 is used, since the earth will then be of a type which oers greater drilling resistance.

In order to positively position the arms 24 relative to housing 22, arms 24 have formed therein a plurality of bores 64 opening through the top surface thereof. As the arms 24 move within bores 30, the bores 64 come into alignment with a bore 66 formed through the upper face of housing 22. A pin 68 may be inserted within bore 66 and an aligned bore 64 to lock the arm 24 against movement within bore 30 of housing 22. This pinning of arms 24 to housing 22 prevents inadvertent moving of the arms relative to the housing and in certain modifications may constitute the only lock against longitudinal movement of the arms 24 relative to housing 22. By spacing the 6 bores 64 in arm 22 at certain intervals, the cutting diameter of the expansion reamer may be increased in increments corresponding to the spacing of the bores 64.

Having now described my novel expansion reamer, it should be apparent that I have provided a rugged reamer which is simple in construction, readily adjustable and which when used in conjunction with an earth auger enable large diameter holes to be drilled easily and speedily with the ordinary drilling rig.

I claim:

l. In an expansion reamer for earth drills adapted to rotate with a spindle and having a pair of projectable and retractable cutter supporting arms, the combination of a housing having a central opening for receiving said spindle and a pair of oppositely disposed elongated apertures nonrotatably and slidably mounting said arms for lateral sliding movement relative 'to said spindle; bores opening into said apertures opposite to the inner ends, re# spectively, of said arms; threaded bores formed in the inner ends of said arms; screw bolts having unthreaded shank portions rotatably disposed, respectively, in said bores in said housing and having threaded shank portions in cooperative threaded engagement, respectively, with said threaded bores in said arms; means holding said bolts against longitudinal movement relative to said housing, said arms sliding within said elongated apertures away from said spindle When said bolts are rotated in one direction and toward said spindle when said bolts are rotated in the opposite direction; and cutting means carried by said arms.

2. The combination set forth in claim l wherein said arms have four sides in sliding engagement with said apertures, respectively, and further comprising alignable bores formed in said housing and arms at right angles to the direction of movement of the latter and a pair of pins removably inserted into aligned pairs of said alignable bores for releasably locking said arms in slidably adjusted position.

References Cited in the file of this patent UNITED STATES PATENTS 757,739 Haines Apr. 19, 1904 1,076,817 Chase Oct. 28, 1913 1,468,774 Caldwell Sept. 25, 1923 1,993,948 Schroeder Mar. 12, 1935 2,613,063 Ransdall Oct. 7, 1952 

